Evaluation of neonatal vitality and blood glucose, lactate and cortisol concentrations in foals of the Paint Horse breed / Avaliação dos padrões de vitalidade neonatal, glicemia, lactato e cortisol em potros da raça Paint Horse

Clinical evaluations of newborns, as well as defining the therapeutic decision, represent significant challenges to the veterinarian. This study aimed to evaluate neonatal vitality using the modified Apgar score and blood glucose, lactate, and cortisol concentrations in newborn equines. Twenty foals of the Paint Horse breed born by normal delivery were evaluated during the first 48 hours of life. The modified Apgar score was determined at birth and 10 minutes later, with values ranging from 0 to 10. Blood samples for the laboratory tests were collected at birth and at 4, 8, 12, 16, 20, 24, 36, and 48 hours. The mean Apgar score was significantly lower at birth than at 10 minutes (p < 0.001). Blood glucose concentrations increased significantly between birth (98.90 ± 35.97 mg/dL) and 8 hours (127.90 ± 27.15 mg/dL), stabilizing after the first 12 hours (148.95 ± 29.59 mg/dL). Serum lactate concentrations showed a significant decrease across the time points tested, with the highest value occurring at birth (5.48 ± 2.17 mmol/L) and stabilizing after 24 hours (2.76 ± 1.31 mmol/L). Cortisol concentrations significantly decreased (p < 0.01) between 4 (10.46 ± 7.46 µg/dL) and 48 hours (5.21 ± 3.35 µg/dL), with the highest value occurring 4 hours after birth. The common occurrence of laboratory abnormalities in healthy newborn foals reinforces the need to conduct regular clinical examinations and to develop laboratory reference values for different breeds and ages.(AU)

A avaliação clínica dos recém-nascidos, bem como a definição da conduta terapêutica adotada representam expressivos desafios ao Médico Veterinário. O objetivo deste estudo foi avaliar a vitalidade neonatal pelo escore de Apgar modificado, glicemia, lactatemia e cortisol em neonatos equinos. Para tal, foram utilizados 20 potros da raça Paint Horse, nascidos em eutocia, durante as primeiras 48 horas de vida. O escore de Apgar modificado foi realizado ao nascimento e 10 minutos após, atribuindo-se notas de 0 a 10. As colheitas das amostras de sangue, para a realização das análises laboratoriais, ocorreram nos momentos ao nascimento, 4, 8, 12, 20 16, 20, 24, 36 e 48 horas de vida. A média do escore de Apgar ao nascimento foi significativamente menor que aos 10 minutos (p<0,001). A glicemia aumentou significativamente entre o nascimento (98,90 ± 35,97 mg/dL) e às 8 horas (127,90 ± 23 27,15 mg/dL), com estabilização após as primeiras 12 horas (148,95 ± 29,59 mg/dL). A concentração sérica de lactato apresentou decréscimo significativo entre os momentos estudados, sendo o maior valor encontrado ao nascimento (5,48 ± 2,17 mmol/L), com estabilização a partir das 24 horas (2,76 ± 1.31 mmol/L). As concentrações de cortisol, reduziram significativamente (p<0,01), entre as 4 (10,46 ± 7,46 µg/dL) e as 48 horas (5,21 ± 3,35 µg/dL), sendo o maior valor encontrado as 4 horas após o nascimento. A ocorrência comum de anormalidades laboratoriais em potros recém-nascidos, aparentemente saudáveis, reforça a necessidade da realização de exames clínicos regulares e o desenvolvimento de valores laboratoriais de referência, em diferentes raças e idades.(AU)

Efeitos do controle de temperatura e da vimpocetina sobre os déficits neurocomportamentais decorrentes do estresse por separação materna em camundongos suíços neonatos / Effects of the temperature control and vinpocetine on neurobehavioral deficits resulting from stress by maternal separation of neonate swiss mice

O estresse durante o desenvolvimento está associado com diversas desordens neurocomportamentais, que podem persistir ao longo da vida. A hiperatividade é um dos transtornos comportamentais que, com maior frequência, observa-se em humanos submetidos ao estresse precoce. Esse transtorno pode ser a manifestação clínica predominante, ou mesclar-se com déficit de atenção, impulsividade e retardo da aprendizagem, constituindo o Transtorno de Déficit de Atenção e Hiperatividade (TDAH), com número de casos diagnosticados em ascensão. Diversos protocolos experimentais utilizam a separação materna (SM) de roedores neonatos para mimetizar as consequências do estresse precoce em humanos. Esta predileção por roedores recém-nascidos se deve à sua equivalência aproximada com fetos humanos no terceiro trimestre da gestação em termos de neurodesenvolvimento, quando ocorre o maior crescimento do Sistema Nervoso Central fetal. Neste trabalho, camundongos suíços neonatos foram submetidos a sessões diárias de isolamento com separação materna, entre o 2º e o 10º dias de vida pós-natal (PN2 a PN10), variando-se a temperatura de isolamento dos filhotes, que permaneciam sem aquecimento (na temperatura do biotério, entre 22 e 25°C) ou eram mantidos aquecidos a 37°C durante essas sessões. Portanto, foram três grupos experimentais: isolamento aquecido com SM; isolamento não aquecido com SM; e controle. Os animais do grupo controle foram pesados em PN2 e PN10 e, prontamente, devolvidos às progenitoras. Todos os animais foram desmamados e sexados em PN21, não sendo perturbados até a realização dos testes neurocomportamentais, a partir de PN30, que incluíram os Testes de Campo Aberto e de Esquiva Inibitória. Num segundo estudo, foram realizadas dosagens séricas da corticosterona basal e dos hormônios tireoidianos nos três grupos experimentais, em PN6, PN10 e PN30...

The stress during development is associated with several neurobehavioral disorders that can persist into postnatal life. Hyperactivity is one of these disorders that is frequently observed in humans early exposed to the early stress. This disorder may be the predominant clinical manifestation, or merge itself with attention deficit, impulsivity and impaired learning, composing the Attention Deficit Hyperactivity Disorder (ADHD), with the number of diagnosed cases on the rise. Several experimental protocols use maternal separation (MS) of newborn rodents to mimic the effects of early life stress in humans. This predilection for newborn rodents is due to its approximate equivalence with human fetuses at the 3rd trimester of pregnancy in terms of neurodevelopment, when there is the greatest growth of the fetal Central Nervous System (CNS). This work was carried out in three separate studies. In the first study, Swiss mice underwent daily sessions of isolation with maternal separation between the 2nd day of postnatal life (PN2) to PN10, varying the isolation temperature of the puppies, that were kept without heating (with the room temperature between 22 and 25° C) or heated at 37 °C during these sessions. Therefore, we had three groups: “warmed isolation with MS”; “unheated isolation with MS”; and control. Control group animals were weighed in PN2 and PN10 and promptly returned to its progenitors. All animals were weaned and sexed in PN21 and were tested from PN30 in the Open Field and Inhibitory Passive Avoidance. In a second study, serum basal corticosterone and thyroid hormones were measured in the three experimental groups at PN6, PN10 and PN30...

Effects of neonatal footshock stress on glucocorticoid and 5-HT2A/2C receptor bindings and exploratory behavior

To investigate the effects of neonatal stress on behavior and neurochemistry, rats were exposed to the footshock stress on postnatal day (PND) 14 or PNDs 14 and 21. Rats were exposed to uncontrollable electric shocks delivered to the floor with a constant current (0.8 mA) for 5 sec period. Daily sessions consisted of 60 trials on a random time schedule with an average of 55 sec. The first exposure to footshocks on PND 14 decreased body weight gain for 1 day. However, the second exposure to footshocks on PND 21 did not affect body weight gain. Exploratory activity was measured by exposing a rat to a novel environment 24 h after experience of footshocks. Similar to the body weight changes, a decreased activity was noted after the first exposure to footshocks, while no changed activity was noted after the second exposure to footshocks. However, the Bmax value of 5-HT2A/2C receptors in the cortex decreased by the second exposure to footshocks, but not by the first exposure to footshocks. Moreover, an autoradiographic study revealed that the density of (3H)dexamethasone binding in hippocampus decreased in rats exposed to footshocks 4 times during PND 14~20. These results suggest that the uncontrollable footshock stress changes 5-hydroxytryptamine and glucocorticoid receptor systems acutely and that the repeated exposure to the same stress may not elicit behavioral alterations by the compensatory activity of young brain although changes in some neurochemistry exist.